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Enumerate all available child items for the root item specified in the pWiaRootItem parameter.
#include "ltwia.h"
L_LTWIA_API L_INT EXT_FUNCTION L_WiaEnumChildItems(hSession, pWiaRootItem, pfnCallBack, pUserData)
Handle to an existing WIA session. This handle is obtained by calling the L_WiaInitSession function.
Valid pointer to a type IWiaItem or IWiaItem2 object (IWiaItem if using WIA Version 1.0; IWiaItem2 if using WIA Version 2.0), which represents the root item for which its child items are being enumerated.
Option pointer to a callback function that receives a pointer to each child item found.
Void pointer that you can use to pass one or more additional parameters that the callback function needs.
To use this feature, assign a value to a variable or create a structure that contains as many fields as you need. Then, in this parameter, pass the address of the variable or structure, casting it to L_VOID *. The callback function, which receives the address in its own pUserData parameter, can cast it to a pointer of the appropriate data type to access your variable or structure.
If the additional parameters are not needed, you can pass NULL in this parameter.
| Value | Meaning |
|---|---|
| SUCCESS | The function was successful. |
| < 1 | An error occurred. Refer to Return Codes. |
This feature is available in version 16 or higher.
The WIA run-time system represents each WIA hardware device in a hierarchical tree of IWiaItem or IWiaItem2 objects (IWiaItem objects if WIA Version 1.0 is being used; IWiaItem2 objects if WIA Version 2.0 is being used). This function enables applications to enumerate the child items for the specified root item.
You should pass a valid pWiaRootItem parameter. First you need to retrieve a pointer to the device's root Item itself by declaring a variable pointer of type IWiaItem* or IWiaItem2*. Next, pass the address of that pointer to the third parameter of the L_WiaGetRootItem function (do not forget to cast it to (L_VOID**)). Then you can pass this same declared variable (after the L_WiaGetRootItem function fills it with a valid item) to the L_WiaEnumChildItems function as the root item for which you wish to enumerate the child items.
LEADTOOLS WIA supports both 32-bit and 64-bit image acquisition for both WIA 1.0 (XP and earlier) and WIA 2.0 (VISTA and later).
For an example, refer to L_WiaGetRootItem.